1. Field of the Invention
The present invention relates to a wall structure of a building, which can be suitably used for a knockdown-type curtain wall of which mullions, transoms, facing members, battens etc. are independently transferred to a construction sites to form exterior wall.
2. Description of Related Art
Conventionally, following two methods are known for constructing facing members such as glass plate and aluminum panel in the above knockdown-type curtain wall.
One method is outside glazing for fitting the facing member to a section formed by mullions and transoms from the outdoor side. The other is inside glazing for fitting the facing member from the indoor side.
The inside glazing is mainly used for a building where a scaffold is difficult to be set up. However, since the facing member cannot be always fitted from the indoor side when there is an obstacle such as a pillar on the indoor side, the outside glazing and the inside glazing may sometimes be combined in a single building.
Incidentally, when the facing member is fitted by the inside glazing, lower periphery of the facing member is held by a holding groove provided on the lower transom and the upper periphery of the facing member is held by a holding piece provided on the outdoor side of the upper transom and an inner batten attached to the transom from the indoor side. The inner batten is attached to the transom by engaging indoor-side end of the inner batten to the indoor-side end of the transom and by engaging the outdoor-side end of the inner batten to a neighborhood of a location for the facing member to be disposed, as shown in U.S. Pat. No. 5,309,689 and Japanese Patent Laid-Open Publication No. Hei 10-131365.
Accordingly, the depth dimension of the inner batten becomes large equaling to the depth dimension of the transom subtracted by a slight part used for connection with the facing member, so that the lower side of the transom is substantially completely concealed by the inner batten. Therefore, the lower side of the transom having no design is not exposed to the indoor space, thus maintaining good appearance of the curtain wall.
On the other hand, an ordinary curtain wall has a vision portion using a facing member composed of glass plate etc. for lighting and a spandrel portion corresponding to a spandrel wall and a hanging wall provided to a slab of a building. Though the inner batten attached to the transom can be seen from indoor in the vision portion, the inner batten as well as the transom is not exposed to the indoor space on account of the presence of the spandrel wall and the hanging wall on the indoor side.
Accordingly, if the inner batten having great depth is used in the spandrel portion without exposing the transom and the inner batten in the same manner as in the vision portion, the component cost cannot be reduced.
Further, in a conventional curtain wall covering the lower side of the transom by the large inner batten, cutoff (waterproofing) treatment is conducted to the gap between both longitudinal ends of the inner batten and the mullions on both sides with a wet seal material irrespective of distinction of the vision portion and the spandrel portion. The cutoff treatment is conducted by piling the seal material up on the backside of both ends of the inner batten in advance and bringing the both ends of the inner batten in contact with the mullion.
However, since the seal material is located on the backside of the inner batten after attaching the inner batten to the transom, the condition of cutoff treatment cannot be checked, so that cutoff performance can become uneven.
An object of the present invention is to provide a wall structure of a building capable of reducing component cost and obtaining stable cutoff performance.
A wall structure of a building according to an aspect of the present invention includes a facing member disposed in a section formed by left and right mullions and upper and lower transoms and an inner batten engaged to the mullion and/or the transom to hold the facing member from an indoor side, in which a cover for covering an indoor side of the inner batten facing the section formed by the mullion and/or the transom is attachably provided.
According to the present invention, since the cover member conceals, for instance, lower side of the mullion and transom, the inner batten itself may be sized to hold the facing member and may have smaller depth dimension than conventional arts. Further, since the cover member is independent of the inner batten, the cover member is not necessarily attached to a portion such as a spandrel portion of a curtain wall where even transom is not exposed. Accordingly, only the inner batten of smaller depth dimension is provided to the spandrel portion and a large cover member as compared to the inner batten is not required, so that production cost therefor can be reduced.
Further, since the depth dimension of the inner batten is reduced, the cutoff treatment between the mullion or the transom and the inner batten can be conducted after attaching the inner batten. In other words, since a space for attaching the cover member is formed on the indoor side of the inner batten, the seal material can be filled after attaching the inner batten using the space. The space can also be used for checking the condition after cutoff treatment, so that cutoff treatment may be conducted again when the condition is bad, thereby stabilizing cutoff performance.
In the above aspect of the wall structure of a building according to the present invention, a holding piece may preferably be provided to an outdoor side of the mullion and/or the transom for holding the facing member from the outdoor side, an outdoor surface of the holding piece having a mark indicating a cutting position of the holding piece, an indoor surface of the holding piece having an engaging portion to be engaged with a post-attached outer batten in place of the cut holding piece, wherein the mark is provided inwardly in width direction relative to the engaging portion.
In other words, even in a curtain wall of inside glazing using the inner batten, the facing member has to be exchanged from the outdoor side on the spandrel portion on account of presence of spandrel and hanging wall. Further, even in vision portion, when an interior material such as casing and curtain box is disposed on immediately indoor side of the transom, since the inner batten is difficult to be detached on account of the interior material, the facing member has to be exchanged from the outdoor side. When the facing member is exchanged, a part of the holding piece of the transom or the mullion is cut from the outdoor side.
However, in cutting the holding piece, the engaging portion of the post-attached outer batten provided on the indoor side of the holding piece can be simultaneously cut. It is strongly desired to eliminate such error during cutting work.
In the present invention, a mark indicating the cutting position is provided on the outdoor side of the holding piece of the curtain wall and the cutting work is conducted along the mark. The mark is provided inward in depth direction relative to the engaging portion.
According to the above arrangement, when the holding piece is cut with, for instance, a hand tool such as a grinder, the engaging portion on the indoor side is not mistakenly cut by cutting along the mark. Accordingly, the holding piece can be easily and securely cut, thus improving workability.
In the above aspect of the wall structure of a building according to the present invention, the facing member may preferably be held by the inner batten and the holding piece through seal members provided on the indoor side and the outdoor side respectively, the seal members having held portions of the same thickness in depth direction.
Conventional inside glazing curtain wall has an outdoor-side seal member pre-attached to the holding piece of the mullion or the transom and an indoor-side seal member fitted between the facing member and the batten after being disposed. The portion held between the holding piece of the pre-attached seal member and the facing member has thickness different from the portion held between the facing member and the inner batten of the post-attached seal member. However, since the pre-attached seal member is disposed on the indoor side and the post-attached seal member is fitted on the outdoor side when the facing member is exchanged from the outdoor side by cutting the holding piece of the mullion or the transom, thickness of the seal member on the indoor and the outdoor side is reversed relative to the other portion without exchanging the facing member, so that the position of the facing member in the depth direction becomes different to impair appearance thereof.
On the other hand, according to the wall structure of a building of the present invention, since the thickness of the indoor seal member and the outdoor seal member, i.e. the pre-attached seal member and the post-attached seal member, is the same, the position of the facing member of the portion exchanging facing member thereof is consistent with the portion without exchanging the facing member in the depth direction, thereby improving appearance thereof.